单项选择题
A. post-80s couples and their friends B. post-80s couples and baby-pooling C. post-80s couples and their parents D. kids and their grandparents
A. The total prevention of tsunamis is possible. B. Rich countries are less affected by tsunamis than poor countries. C. Approaching tsunamis can possibly be picked up by sensors. D. An early warning system is effective when a tsunami is close by.
A. save money B. connect over the Internet C. buy different items D. make friends